That’s right, we are exploring the world of the weird and wonderful beaked whales! This week, learn about two of the members of the beaked whale family: Cuvier’s beaked whales and the Northern Bottlenose Whale.
Whales with beaks!
Did you know there were whales with beaks? Well there are, and they are kind of funny looking, but very cool. There are a total of 21 species, but we don’t know much about most of them because they are so hard to find and observe. I am going to talk about 2 of the more well-known species, Cuviers and the Northern bottlenose whale.
Cuvier’s Beaked Whale (Ziphius cavirostris)
Cuvier first described this species in 1823 based on a partial skull, but thought it was a fossil because of the very dense bone structure. It wasn’t until 1872 that another man, Turner showed that it was a living, or extant species. So even before we started learning about them they were already being tricky!
The dense bone and a prenarial (in front of the nares) cavity is unique to this species compared to others in the Ziphius genus, and is where the cavirostris in their name comes from. But they have another name, the goose-beaked whale, though I am not sure that they look like they have goose beak. In fact, I think their name should be related to mimes – look at the white coloration of the head in the picture below, looks like a mime whale to me!
But I digress. They do look pretty cool though, with the panda like rings around each eye. At 15-23 ft, 4,000-6,800 lbs, that is a big panda whale! They can live up to an estimated 60 years, though the oldest stranded animals were 30-40 years old. They are sexually mature around 11 years and are thought to reproduce at a low rate every few years.
This is the most frequently sighted of all beaked whale species, found in oceans worldwide (except arctic and Antarctic), and it also has the most extensive range – found in tropical to cold-temperate waters. They are found in open ocean, deep water, which is one reason they are hard to observe.
These whales are often alone, or in social groups of 2-7. Individual whales are identifiable through cookie cutter shark bite scars, and, for males, from the teeth marks they leave when fighting each other. Photo-ID has shown individuals re-sighted for up to 15 years, showing that there may be site fidelity to particular areas. These are areas where the deep water is close to shore, like Hawaii and the Bahamas, which makes finding the animals easier than more offshore populations.
Living and feeding in deep water it isn’t surprising that they have the record for the deepest and longest dive for any mammal – almost 3000 meters (about 2 miles) and 137.5 minutes! Dives of 1000-2000m are common. They are diving for squid mainly, and have been known to consume at least 47 different species! They will also snack on fish and crustaceans. Like other beaked whale species, they don’t have many teeth – males have 2 teeth in the lower jaw, similar to tusks, and females don’t have any visible teeth. Without teeth, they rely on suction (aided by their 2 throat grooves) to slurp of their favorite prey. But the coolest thing about this species is their flipper pockets. That’s right they have pockets! Everyone loves pockets – I wish dresses had pockets! These animals have little pockets where their flippers fit into that makes them more streamlined– an important adaptation for their deep diving behavior. Flipper pockets for the win!
Northern Bottlenose Whale (Hyperodon ampullatus)
This is the largest of the beaked whale species in the North Atlantic, reaching up to and estimated 16,500 lbs and 28.2ft females) to 36.7ft (males). They get their name, ampullatus, from the Latin ampulla for the bottle shape of their beak. Indeed, take a look, it looks similar to that of a bottlenose dolphin!
The main distinguishing feature of this whale is its fivehead. No that isn’t a typo… that is a term people use for someone with a large forehead (get it fourhead)? I would say these whales definitely have a large forehead, or melon as it is called in cetaceans. The melon also becomes more pronounced as they age, becoming steeper and flatter.
What is a good use for a steep flat melon? Well for the males of this species, all the better to head butt with! Unlike the Cuvier’s (and other beaked whales) who rake each other with their teeth, these males will use their large heads to hit one another. But the males do have teeth – small conical ones that angle slightly forward and are visible on the tip of the lower jaw. They may have a second pair hidden in the gums behind the exposed teeth as well. They also have 10-20 vestigial teeth in the gums of the upper and lower jaw. Females and juveniles all teeth remain embedded in the gums.
Northern bottlenose whales live in deep water, usually greater than 6,500ft, in cold, temperate to sub-arctic oceanic waters. They are often associated with submarine canyons, sea mounts and continental slopes. They can be found alone, or in social groups of 4-10 individuals. But sometimes they have found up to 50 in a loose aggregation. It is always interesting when larger groups like this happen when a species is normally found in smaller groups – why does this occur? Is it that they were all there because the food was good (so they just happened to be around other whales)? Or does this serve some social function within the society (like mating, reinforcing social bonds)? We still have much to learn about the social structure of this species, and most beaked whales.
Like other beaked whales they are good divers, holding their breath for 10-60 min (though can hold their breath for 2 hours) and diving 2,600-5000ft to feed on deep sea cephalopods, fish, shrimp, sea cucumbers and sea stars. I will tell you that I had never heard of a cetacean eating sea stars before!
They are estimated to live up to at least 37 years, becoming sexually mature at 7-11 years of age. It was thought that they calved every 2+ years, but a recent paper by Freyer et al. in the journal PLOS ONE used isotopes in teeth from whales from the whaling era and showed that weaning didn’t occur until 3-4 years of age. This new evidence means that it will take longer for a population to recover because they are not calving as often as previously thought.
The reason why this is perhaps more important for this species than other beaked whales is that they have spermaceti – like sperm whales do. They were hunted for this oil, and also for pet food. The whalers exploited the northern bottlenose whale’s curiosity and social bonds. The whales would often investigate stationary vessels and would stay with injured members of their group. This made them easy prey for the whalers. You may think that this was a thing of the distant past – but the fishery only closed in 1970, although there is still a fishery in the Faroe Islands. More than 80,000 whales have died.
Perhaps the biggest threat to most beaked whales, including Cuvier’s and the norther bottlenose whale, is noise. Because they are often in deep canyons diving for food, they are more likely to be affected by military sonar testing done in these areas. These loud sounds can startle them causing them to rapidly rise to the surface, as if running away from a predator. They have behavioral and physiological ways to prevent or deal with the consequences of decompression sickness, but not when they surface too quickly. Unfortunately, this can lead to stranding events, and often mass strandings where large groups wash onshore.
Knowledge is power, but we know little about these enigmatic group of whales. Even though they live far from us, we can have great impacts on their populations. We need to learn more about them, to know just how to protect them.